In a conventional dry-cleaning machine the articles being cleaned, usually clothing, are trumbled in a perforated drum while a chlorinated and/or fluorinated-hydrocarbon solvent such as perchlorethylene, trichlorotrifluoroethane, or trichloromonofluoromethane is passed through them. Water and a soap or detergent may be added to the solvent and the mixture is continuously filtered and recirculated until the garments are clean.
For drying it is conventional to admit air to the drum while evacuating it and condensing the solvent from the evacuated air-vapor mixture. Unfortunately with such a system as the garments dry the percentage of solvent vapor in the extracted gas decreases until the condenser is almost totally ineffective.
Other drying methods have been proposed which use, for instance, complicated indirect heating of the solvent-soaked garments for vaporization of the solvent. None of the methods allow the garments to be dried quickly and inexpensively with a good recovery of solvent. Furthermore none of the methods are effective for use with objects other than garments. Degreasing of metal parts, cleaning of leather or hides, or the like is virtually impossible with the known methods since they are either heated excessively or insufficiently.